Lab Test

Culture, Blood

Blood Culture, Sepsis, Bacteremia, Fungemia

Test Codes





  • One blood culture set contains an aerobic and an anaerobic bottle.
  • Blood should be obtained prior to the administration of antimicrobial agents.
  • Skin antisepsis is critically important and there must be meticulous preparation of the skin with a bactericidal agent (ChloraPrep).
    • ChloraPrep cannot be used on children less than 2 months of age! Refer to the Specimen Collection Manual for information on venipuncture . If using an iodophor such as Betadine, it must be allowed to dry completely to be effective. Both alcohol and iodine MUST be allowed to dry before starting the venipuncture.
  • Avoid drawing blood through an indwelling intravenous or intra-arterial catheter unless it is needed specifically to evaluate a potential catheter-related infection. Blood obtained from an indwelling catheter is the least desirable specimen and must be accompanied by a second set of blood cultures obtained by venipuncture.
  • Follow standard (universal) precautions: wear gloves and handle all inoculated bottles as though capable of transmitting infectious diseases.

Specimen Collection Criteria

Collect: Blood Culture set (one aerobic and one anaerobic blood culture bottle). Collect blood using a syringe or a butterfly collection system attached to a Vacutainer® directly into the blood culture bottle.

  • For adults, 16-20 ml of blood should be obtained for one aerobic and one anaerobic blood culture bottle. (8-10 mL per bottle)
  • For children, up to 3.0 ml of blood should be drawn into the pediatric blood culture bottle.

NOTE: Blood volume is one of the most important variables in detection of a septic episode. Submitting less than the minimum volume of blood may compromise the quality of the blood culture. Hand write on the specimen label the time, date, and site of the collection and the name of the collector. Use a marker to indicate on the side of the bottle how much blood should be added.

It is recommended that 2-3 sets of blood culture, be obtained within 24 hours and that no blood cultures be obtained after that time unless the patient's condition changes. If at all possible, blood should be obtained prior to the administration of antimicrobial agents.

Fungi (Yeast): For adults, draw 10 mL of blood into the adult Isolator tube, mix well. Order a Fungus Culture.
For pediatric patients, draw 1.0-1.5 ml of blood into the pediatric Isolator tube, mix well. Order a Fungus Culture.


  1. More than 3 blood cultures orders within 24 hours requires the approval of the Microbiology System Director/Associate Director.
  2. If a fastidious or unusual organism or a mold is suspected, the laboratory must be notified.
  3. If a Select Agent is suspected, the Microbiology System Director/Associate Director or supervisor MUST be notified prior to submitting the cultures to the Laboratory.
  4. Finger stick or heel stick collections are not acceptable for Blood Culture collection.

For more specimen collection information, click here.

Physician Office/Draw Specimen Preparation

  • Protect from direct sunlight.
  • Maintain at room temperature (20-26°C or 68-78.8°F). Do not refrigerate or freeze.

Preparation for Courier Transport

Transport: Blood culture bottles, at room temperature (20-26°C or 68-78.8°F).

Rejection Criteria

  • Bottles or Isolator tubes not labeled or improperly labeled.
  • Leaking bottles or Isolator tubes.
  • Cracked, broken, or externally contaminated specimens.
  • Specimens collected in improper or "outdated" bottles or tubes.
  • Refrigerated or frozen specimens.
  • Specimens received more than 24 hours after collection.

Inpatient Specimen Preparation

Send specimens to Microbiology Laboratory immediately.

If blood bottles are to be sent through the pneumatic tube system, it is imperative that no more than 2 bottles (1 set) be inserted into one carrier. Two bottles in cones can be placed into one pneumatic tube - "bottom to bottom." Additionally, the bottles MUST be safely cushioned between two foam inserts within the carrier.

In-Lab Processing

Blood cultures should be transported to the Microbiology Laboratory as soon as possible. Follow standard (universal) precautions: wear gloves and handle all inoculated bottles as though capable of transmitting infectious diseases.


Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 8 hours*
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable

*Specimens greater than 8 hours old will require approval of the Microbiology System or Associate Director or Supervisor before testing.

Specimen Storage in Department Prior to Disposal:

Room Temperature (20-26°C or 68-78.8°F): Positive bottles will be held for one week following detection of growth. Negative bottles will be disposed after testing is complete (five days).


Dearborn Microbiology Laboratory
Taylor, Trenton and Wayne sent to Dearborn Microbiology Laboratory for testing.

Royal Oak Microbiology Laboratory
Farmington Hills, Grosse Pointe, and Troy sent to Royal Oak Microbiology Laboratory for testing.


Sunday – Saturday, 24 hours a day.
Preliminary results available in 24 hours.
Final negative results in 5 days.

Reference Range


Test Methodology



The presence of microorganisms in the blood may indicate a septic event. Blood cultures in which one set of the two or three sets of bottles is growing microorganisms known to be skin flora may represent contamination acquired during venipuncture.

Clinical Utility

The detection of viable microorganisms in a patient's blood has great diagnostic and prognostic importance. A positive blood culture is a critical result. All positive blood culture results are called to the patient's physician/health care provider as well as documented electronically. Laboratory reports include all salient information such as the Gram stain morphology, the number of blood cultures that are positive and any additional identification information that can assist with determining the appropriate course of therapy for the patient.

Clinical Disease

When bacteria or fungi multiply at a rate that exceeds the capacity of the reticuloendothelial system to remove microorganisms, bacteremia or fungemia results. Persistent bacteremia occurs with failure to localize a bacterial infection in the extravascular tissues or failure to remove, drain or adequately treat a focus of infection. Each condition varies but generally septic patients present with fever (> or = 38°C) or hypothermia (< or = 36°C), leukocytosis (> 10,000) with a left shift, granulocytopenia (< 1000) or any combination of the above.

Septicemia represents a medical emergency that usually requires the prompt institution of antimicrobial therapy. The choice of antibiotics may be empirically determined based upon several types of information: the patient's underlying disease, antedecent procedures or instrumentation, the presence and site of preexisting infection, prior antimicrobial therapy, the endemicity or epidemicity of certain microorganisms in the hospital and the antimicrobial susceptibility of these microorganisms.

Disease Reporting

Most cases of blood stream infection are not reportable; however, they must be reported if a critical microorganism is recovered. For more information on reportable diseases, contact the Epidemiology Department or the Microbiology System/Associate Director or Supervisor at each hospital.


Identification of microorganisms that may be involved in nosocomial transmission must be considered with each positive culture. These include microorganisms such as methicillin- or oxacillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus species (VRE), Mycobacterium tuberculosis and antimicrobial-resistant bacteria. For more information about nosocomial transmission, contact the Epidemiology Department or the Microbiology System/Associate Director or Microbiology Supervisor at each hospital.

Incubation Period



Microorganisms usually enter the blood from extravascular sites via lymphatic vessels. Direct entry of bacteria or fungi into the bloodstream occurs with intravascular infections such as infective endocarditis, infected arteriovenous fistulas, mycotic aneurysms, suppurative phlebitis, infected intravenous catheters and infected indwelling arterial catheters.


  1. Baron, E.J., M.P. Weinstein, W.M. Dunne, Jr., P. Yagupsky, D.F. Welch, and D.M. Wilson. 2005. Cumitech 1C, Blood Cultures IV. Coord.ed. E.J. Baron. ASM Press. Washington D.C.
  2. Washington, J.A. 1978. The Detection of Septicemia. CRC Press General Detection and Interpretation, Inc., West Palm Beach, Florida.
  3. York, Gilligan, P., K. Alby, M.K. 2016. Blood Cultures. Clinical Microbiology Procedures Handbook 4thed. Leber, A.L., Ed. in Chief. ASM Press. Washington D.C., pp. 3.4.1.

CPT Codes

LOINC:  600-7


Last Updated


Microtainer® and Vacutainer® are registered trademarks of Becton, Dickinson and Company.
UroVysion® is a registered trademark of Abbott Laboratories. ThinPrep® is a registered trademark of Hologic, Incorporated.